1. Field of the Invention
The present invention relates to the drilling and completion of well bores in the field of oil and gas recovery. More particularly, this invention relates to an apparatus adapted to provide a spacing mechanism between relatively-long strings of tubular string (e.g., a production tubing string, and the like) extending within a well bore. The apparatus may be used in an Upper-completion Single Trip (“UST”) system, and may include a Hydraulic Internal Seal Receptacle (“HISR”) assembly (also known as a “One Trip Stinger Assembly”) as a component thereof.
2. Description of the Related Art
In the oil and gas industry, production string is run thousands of feet into the earth. Well bores are typically drilled by rotating a drill string comprising a plurality of drill pipe segments serially connected to a bottom hole assembly and a drill bit thereby creating the well bore. As the well bore is drilled, tubular casing may be placed in the well bore to protect the well bore. The casing may then be cemented as desired. Progressively smaller diameter casing may be used as the well bore is drilled deeper until a hydrocarbon-bearing formation is penetrated. Once the production casing is in place, production pipe or tubing may also be run within the casing string in the well bore. Production tubing strings may typically be thousands of feet in length, in order to place the lower end of the tubing adjacent the hydrocarbon-bearing subterranean formation. Such systems may be utilized on land or offshore.
The temperature of the long production strings is adapted to change over time. For instance, during production, the temperature of the strings increases. This increase in temperature leads to concomitant increase in the length of the string. If the string is anchored on each end, then the increased length causes compressive stresses to accumulate on within the tubing string.
Similarly, if the tubing string is cooled, the overall length of the string is reduced. Thus, the string is prone to be susceptible to tensile stresses. Due to the overall length of the tubing string, changes in temperature e.g. may impart significant forces thereupon which are detrimental to the operation of the tubing string. For example, when being run downhole, the relatively cool temperature of the brine cools the tubing string such that the metal tubing string contracts. When in production the hydrocarbons passing through the tubing string forces the tubing string to expand its overall length. When operated in a deviated or horizontal well, these forces are exasperated.
To reduce this associated stress, it is desirable to provide a spacing mechanism. The mechanism should be adapted to be placed in the string and accommodate the changing length of the string, thus reducing the associated stresses. Thus, it is desirable to provide a spacing function in the tubing string to act to compensate for the expansion and contraction of these relatively long tubing strings to reduce the associated stresses therein.
It is known to provide spacers in the production string during completion. However, present assemblies are known to prematurely or accidentally actuate, causing difficulties while running downhole. For example, if the spacer tool contacts an unintended obstruction downhole, the tool may accidentally, prematurely release or actuate, thus hampering the running in of the tool.
In some prior art methods, a spacing device is provided which is assembled utilizing shear pins. To activate the spacing device, the shear pins are sheared. However, with such systems, the spacing device may be accidentally actuated by the tool contacted unanticipated debris or an obstruction downhole. Thus, the spacing device begins to function long before desired.
Further, during the completion of the well, it is needed to perform additional functions downhole, such as aligning and running the production tubing in the packer downhole, and locking the production string into a packer downhole.
Presently, it is known to perform each of these functions in separate trips into the wellbore. Each trip down the wellbore adds significant cost and time to the completion project. Thus, it is desirable to perform each of these three functions in a single trip to reduce the overall cost of the project, reduce the number of components utilized in the job, and reduce the number of components falling downhole (e.g. clamps).
Also, desirable to be able to rotate the entire spacing assembly, should any downhole component become lodged and rotation is necessary to attempt to dislodge the assembly.
In other situations, it is desirable to provide a latching mechanism and a mule shoe assembly, which does not require rotation of any downhole components to operate. For instance, when performing the installation of permanent downhole gauges or intelligent-type system, rotation is not possible, as these systems typically include the use of hydraulic lines, electric line, or fiber optics.
Thus, there is a need for an apparatus that provides a spacing function along a tubing string wherein the apparatus is not prone to premature or accidental activation. Preferably, the system is capable of performing the functions of providing a spacer, aligning and running the production tubing in a packer, and locking the production string into the packer in a single trip downhole, thus significantly saving time and cost of the completion process. It is also desirable that the system also provide means for selectively breaking the string such that components above the system may be removed or repaired; once the repair is completed, the system should be able to rejoin the string.
Embodiments of the present invention are directed at overcoming, or reducing and minimizing the effects of, any shortcomings associated with the prior art.